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Re: Feathers for S excretion



----- Original Message -----
From: "Steve Brusatte" <dinoland@lycos.com>
To: <dinosaur@usc.edu>
Sent: Wednesday, March 28, 2001 12:29 AM
Subject: Re: Feathers for S excretion


> I don't know if anybody has mentioned this on the list yet, but what about
mammals??  During the same general time that feathers were evolving mammals
were evolving.  The first feathered animals (birds/dinosaurs) and the first
mammals were small, and both likely exploited the insect-eating niche.  Why,
they, would birds have to evolve these elaborate, sulfur-intwined feathers
to get rid of excess sulfur while mammals evolved hair?  After all, much of
the diet may have been the same.

Well, I have suggested that hair might actually have evolved for the same
reason. Hairs are shed all the time, not unlike feathers...

> David (I believe) said that while hair does contain some sulfur (disulfide
bridges, and such), feathers contain a much higher amount of sulfur.  This
begs the question: if the first feathered animals and the first mammals were
eating the same relative amount of sulfur, why did birds evolve these
elaborate feathers?  Were the kidneys of mammals that much more efficient
than those of birds?

Though some say so, bird kidneys just work differently, AFAIK.

> And, what about modern mammals (Insectivora)? How do they git rid of all
of this sulfur that they ingest?  Many on this list have said that they
kidneys are not able to perform this task efficiently.  Then, I ask, how do
insectivorous animals get rid of this sulfur?  It isn't through feathers.

I don't know, but see above.

Overdue answers, especially on the flight thread to which HP Tim Williams
has contributed so much, forthcoming...

*************************************
QUANTUM physics pops up everywhere. Reader Joe Morice bought some grape nuts
produced by Kraft. The packet informed him: "Contents may have occured
during shipping and handling."
    Schrödinger's cereal?
                    New Scientist 10 March 2001
*************************************
I'm not trying to start a politics thread, at least not onlist; but I wrote
some exaggerations and other nonsense about the loser of the US presidential
elections, US President G. W. Bush, a few months ago -- just yesterday he
has confirmed everything by suggesting to leave the Kyoto Protocol for
benefitting the economy and by saying that the Kyoto Protocol is useless
unless the developing countries are included. >:->